Sickle cell disease (SCD), the most common life-shortening genetic disorder, affects primarily African American youth in the U.S. SCD has its first health impact in infancy but more severe complications (e.g. organ damage, chronic pain, risk for early mortality) emerge in adolescence. Effective self-management skills are critical to decrease complications and mortality in adolescents with SCD. Prior studies in SCD self- management have focused on a single dimension (e.g. adherence) and assumed a high level of patient motivation and engagement. However, our pilot work indicates a compelling need to develop tailored, group- based interventions to increase motivation and engagement in this particularly vulnerable population to improve their self-management skills more broadly. Behavioral activation (BA) or the knowledge, self-efficacy, readiness and skills necessary to manage one's health, is potentially an important mechanism for improving disease self-management and preventing poor outcomes. We developed a novel, tailored, group-based self- management intervention, SCThrive, to improve BA and self-management in adolescents and young adults (AYAs) with SCD. SCThrive uses a mixed in-person and online format and is supported by a mHealth tool designed with input from AYAs with SCD, iManage. The objective of this application is to determine SCThrive's feasibility, acceptability and preliminary efficacy ia the following specific aims: 1) determine the feasibility and acceptability of the SCThrive intervention for AYAs with SCD, and 2) conduct a pilot randomized trial (N=64) to determine whether the refined SCThrive intervention is superior to an attention control in increasing BA in AYAs with SCD ages 13-21 (stratified by age and disease severity). We hypothesize that participation in SCThrive over a 6-week period as compared to attention control will lead to increased BA (primary outcome) at post-treatment. For Aim 2, we will continue to assess feasibility and acceptability and examine whether the SCThrive intervention is associated with improvements in BA 6 weeks after treatment. We will also explore whether SCThrive is associated with greater improvements in self-management behaviors and quality of life (secondary outcomes) compared to attention control 6-weeks after treatment. The team has expertise in behavioral medicine, hematology, and bioinformatics and has collaborated on pediatric SCD intervention studies that lay the foundation for this proposal including the development of the iManage tool. The study is significant because it addresses the need for developing behaviorally-activated patients with SCD who are engaged, collaborative partners in managing their health to decrease symptoms. The proposed research is innovative because it challenges the prevailing research practice of using individual, one-dimensional, and investigator-designed behavioral interventions. Results from this developmental/exploratory project will lay the foundation for an R01 application to examine SCThrive's efficacy in a fully powered randomized multisite trial.